UIPanGestureRecogniser not working properly - ios

Question

I've got this function to handle the dragging of a view:+
func handlePan(recognizer:UIPanGestureRecognizer) {
let translation = recognizer.translationInView(self.view)
let newCenter = CGPointMake(self.view.bounds.size.width / 2,
recognizer.view!.center.y + translation.y)
print("the translation x:\(translation.x) & y:\(newCenter.y)")
if (newCenter.y >= 397 && newCenter.y <= 632) {
recognizer.view!.center = newCenter
recognizer.setTranslation(CGPointZero, inView: self.view)
}
}
The positions are right.
However, the view that I need to move often blocks while I'm dragging, so I need to stop and start dragging it again.
How can I solve this?
EDIT: My code looks like this now, but I still got the problem:
func handlePan(recognizer:UIPanGestureRecognizer) {
let translation = recognizer.translationInView(self.view)
switch recognizer.state {
case .Ended:fallthrough
case .Changed:
let newCenter = CGPointMake(self.view.bounds.size.width / 2,
recognizer.view!.center.y + translation.y)
print("the translation x:\(translation.x) & y:\(newCenter.y)")
if (newCenter.y >= 397 && newCenter.y <= 632) {
recognizer.view!.center = newCenter
recognizer.setTranslation(CGPointZero, inView: self.view)}
default : break }
}

Answer 1

Since I don't know the other parts of your code, this is a section assuming what yours might and should look like:
class ViewController: UIViewController {
// Gesture function
func panAround(recognizer: UIPanGestureRecognizer) {
switch recognizer.state {
...
case .Changed:
let translation = recognizer.translationInView(yourView)
let newCenter = CGPointMake(self.view.bounds.size.width / 2,
recognizer.view!.center.y + translation.y)
print("the translation x:\(translation.x) & y:\(newCenter.y)")
if (newCenter.y >= 397 && newCenter.y <= 632) {
recognizer.view!.center = newCenter
// Updating the UI whenever there is a "small change"
updateUI()
recognizer.setTranslation(CGPointZero, inView: self.view)
}
...
}
}
private func updateUI() {
yourView.setNeedsDisplay()
}
NOTE: The code above WILL NOT work directly by copy and pasting, I am merely pointing out where you can make adjustments.